The earliest age at which individuals can enlist in any branch of the U.S. military is age 17, but at this age, they must have parental consent. However, the average age is higher given that some people enlist later. The maximum age for most branches is 35. On its recruiting website, the U.S. Army reported an average enlistment age of just under 21 in 2012. This was slightly lower than the average age from 2010 and 2011.

Other Branches

On its website, the U.S. Navy doesn't provide information about the average enlistment age. It notes that you can join from ages 17 through 34. The U.S. Air Force Personnel Center website doesn't provide an enlistment age average, but it does note that age 29 is the average age of its enlisted force, as of 2013.

About the Author

Neil Kokemuller has been an active business, finance and education writer and content media website developer since 2007. He has been a college marketing professor since 2004. Kokemuller has additional professional experience in marketing, retail and small business. He holds a Master of Business Administration from Iowa State University.